The re-election of the federation's biggest grumbler means Stephen Harper will spend much of the time before the next election nursing a political headache.
Kathleen Wynne's Ontario Liberals haven't just crossed swords with Mr. Harper's federal Tories, they have become a government of grievance against Ottawa. And that could weigh down Mr. Harper's re-election hopes, which depend on winning swing voters in Ontario.
Of course, Mr. Harper could choose to find silver linings. Ontarians have a habit of choosing different parties in Ottawa and Queen's Park. After so many years of provincial Liberal rule – and scandals – another term might create pent-up demand to punish Grits by the time next year's federal vote comes.
But he faces a bigger headache if Ms. Wynne keeps using the premier's megaphone to tell Ontarians that Mr. Harper won't lift a finger to help them, whether it's on transfer payments, the Ring of Fire or pensions.
Mr. Harper can't win a majority government if he just shares Ontario's seats. His Conservatives are marginalized in Atlantic Canada and Quebec, so without a solid majority of Ontario seats he can't retain a firm hold on power. And that means in Ontario, he has to win votes beyond his Conservative base.
Ontario used to be seen as the Good Samaritan of the federation, keen to serve the national interest. But manufacturing jobs were lost, and there's a lukewarm economy that's downright weak in once-prosperous places such as London. The province's politics are more cantankerous as people are more inclined to feel aggrieved.
And Ms. Wynne has gone out of her way to tell folks that Mr. Harper is short-changing them. Her Ontario is the lead griper against the feds.
Oh sure, Mr. Harper's core political supporters will discount that as Liberal politicking, and some others will dismiss it as just more federal-provincial bickering.
Some of it clearly is that, at least in large measure. Ms. Wynne makes it sound like Northern Ontario would already be richer than northern Alberta if only the feds would pry open their purse to develop the Ring of Fire mining project – but Mr. Harper's government couldn't just sign a cheque today and set it rolling.
Mr. Harper's Conservatives had also been willing to grind their axe at the provincial Liberals. The late Jim Flaherty surprised Ms. Wynne by suddenly changing transfer-payment rules that Ottawa created in 2010 just when they were about to benefit Ontario – putting a $641-million hole in Ontario's budget.
Now this election has set Ms. Wynne on a path to more complaints that Mr. Harper's isn't taking care of Ontarians.
Her big-ticket election promise to create an Ontario pension plan to top up the Canada Pension Plan is based on the argument that Ottawa should have done more to help Ontarians retire, but didn't – so the province had to step in. It's an argument her government is likely to keep repeating, loudly, as they follow through.
Another big-money election promise, to sink $1-billion into the Ring of Fire, offers plenty more opportunity to tell the province Mr. Harper isn't helping Ontario.
That's politics. But it can hurt a prime minister, because swing voters often see their premier as a guardian of local interests. And Ontario is the one place where just winning the Conservative base isn't good enough. Mr. Harper won a relatively slim majority government only because he won two-thirds of Ontario's seats.
He did that by taking 44 per cent of the vote – far more than his hard-core Tory base of perhaps 30 per cent. Mr. Harper has to fight for Ontario swing voters. And the chief executive of the provincial government is telling them he's shortchanged them.
Mr. Harper has usually managed to keep squabbles with premiers relatively cool. Premiers haven't really taken to campaigning head-on against him. But Ontario has just re-elected a premier who has become his biggest headache.